Roof carrier systems have recently come into use in many motor vehicles as leisure habits have changed. Such roof carrier systems are designed, for example, for mounting ski racks, cycle racks, roof boxes and the like to transport leisure and sports equipment and related accessories. In conventional roof carrier systems there are usually provided two rails that extend on the left and right-hand sides of the roof edge in the longitudinal direction of the vehicle. Such longitudinal rails are constructed from a single member or from multiple members.
Single-member rails comprise an elongated connecting member having at its ends fixing mounts that are bolted to the vehicle roof. This type of construction requires complex fabrication steps to manufacture the rail so as to ensure that the required properties and geometries of a particular design and the necessary mechanical strength and stiffness are obtained.
Multiple-member rails consist substantially of two mount members and a central connecting member inserted between the mount members. Similarly with a multiple-member rail, the mount members are bolted to the vehicle roof and in addition there can be provided intermediate supports likewise bolted to the vehicle roof and suitably attached to the central connecting member.
The conventional rail systems have the significant disadvantage that the vehicle roof has to be provided with appropriate apertures and/or holes to enable the mount members to be fixed to the vehicle roof. With holes of this kind in the vehicle roof, any inadequacy in sealing creates the risk of corrosion which, once it reaches an advanced stage, can result in the mount members breaking off, or at least in a deterioration in the appearance of the vehicle. Also, because they are complex components, conventional rails have to be fabricated in a separate manufacturing step which has the disadvantage of making the roof carrier system more expensive.
Consequently, it is the underlying object of the invention to provide a roof securing system which can be fabricated in a more advantageous manner and which allows greater flexibility with regard to design and function.